tdf#107801 docx export: support w:kern

Writer only enables or disables pair kerning (autokern).
Word uses a minimum font size to determine which characters
to kern. Since these documents are round-tripping through
Writer, and every size is kerned by Writer, the minimum size is
forced to 1pt and the original minimum font size is lost.

This is a followup to commit 38b0c24fa5cbb4246e03d77ac022dfdc9fdede03
for related tdf#105454 DOCX import: fix unwanted enabled-by-default
kerning.

Tested in Word 2003, 2007, 2013.

Change-Id: I7678a544f455fd06bec5e7d864b5c27ab26bf6d3
Reviewed-on: https://gerrit.libreoffice.org/37574
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Justin Luth <justin_luth@sil.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

1 files changed, 5 insertions, 2 deletions

diff --git a/sw/source/filter/ww8/docxattributeoutput.cxx b/sw/source/filter/ww8/docxattributeoutput.cxx
index 83dfe43b5372..f82667c6ed2c 100644
--- a/sw/source/filter/ww8/docxattributeoutput.cxx
+++ b/sw/source/filter/ww8/docxattributeoutput.cxx
@@ -6483,9 +6483,12 @@ void DocxAttributeOutput::CharWeight( const SvxWeightItem& rWeight )
         m_pSerializer->singleElementNS( XML_w, XML_b, FSNS( XML_w, XML_val ), "false", FSEND );
 }
 
-void DocxAttributeOutput::CharAutoKern( const SvxAutoKernItem& )
+void DocxAttributeOutput::CharAutoKern( const SvxAutoKernItem& rAutoKern )
 {
-    SAL_INFO("sw.ww8", "TODO DocxAttributeOutput::CharAutoKern()" );
+    // auto kerning is bound to a minimum font size in Word - but is just a boolean in Writer :-(
+    // kerning is based on half-point sizes, so 2 enables kerning for fontsize 1pt or higher. (1 is treated as size 12, and 0 is treated as disabled.)
+    const OString sFontSize = OString::number( (sal_uInt32) rAutoKern.GetValue() * 2 );
+    m_pSerializer->singleElementNS(XML_w, XML_kern, FSNS( XML_w, XML_val ), sFontSize.getStr(), FSEND );
 }
 
 void DocxAttributeOutput::CharAnimatedText( const SvxBlinkItem& rBlink )